is there a way to do this without using excel? i want to see how it can be done on a calculator or mental math if that makes sense. Thanks!

8. (2 points) Consider the following information: Probability of State of Economy .15 .35 State of Economy Boom Good Poor Bust Rate of Return If State Occurs Stock A Stock B .45 .10 -.01 -.06 -12 - 20 .55 .16 Stock C .27 .08 -.04 -.09 .25 .05 a) Your portfolio is invested 40 percent cach in A and C, and 20 percent in B. What is the expected return of the portfolio? (1 point) b) What is the variance of this portfolio? The standard deviation? (1 point)